1. Technical Field
The present invention relates to a staple forming arrangement that constitutes a part of a stapler, in which a workpiece, primarily a sheaf of papers, is stapled together. The arrangement includes a bending punch, which is driven by a drive mechanism and which bends elongated staple blanks over a bending cushion. The staple blanks, which are stored in a magazine in the stapler, are fed to the bending cushion by an integral feeding device and are bent essentially into a U-shape having a crown and a first and second leg respectively, whereupon the bending punch is withdrawn from the bent staple. After the removal of the bending punch, the bent staple is fed by the feeding device to a staple guide channel in which the staple is driven into the workpiece by a drive blade incorporated in the stapler in order to staple the workpiece together.
2. Background Art
Staple forming arrangements of the type described above are commonly used and essential components of modern staplers as used, among other applications, in copying machine installations. An arrangement of this type is described in the applicant's own U.S. Pat. No. 5,794,833, which application does not, in itself, relate directly to the staple forming arrangement.
A disadvantage of previously known arrangements is, however, that the legs of the formed, U-shaped staple blank may, before it is fed to the staple guide channel by the feeding device, spring back to the extent that the staple, when fed forward, either does not enter the guide, or enters the guide misaligned. This results in either faulty stapling or, in the worst case, failure to complete stapling due to jamming of the stapler.